Ascientist tries to mate the two similar-looking fruit flies drosophila melanogaster and drosophila simulans. but he finds that they are unable to produce viable offspring. what kind of evolutionary barrier could this be?
chromosomal
postzygotic
physical

answer; /// i believe that the correct answer is (50%);

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."